Q5. In Marchantia, NCERT Figure 3.2 shows a female thallus and a male thallus. What does each bear?
The female thallus bears archegoniophores (with the archegonia); the male thallus bears antheridiophores (with the antheridia) (NCERT Figure 3.2, page 28).
Q6. How does the leafy stage of a moss arise?
From the secondary protonema, as a lateral bud (NCERT page 30).
Q7. Name the structures by which liverworts reproduce asexually, and say where they develop.
Gemmae, green multicellular asexual buds, which develop in small receptacles called gemma cups on the thalli; liverworts also multiply by fragmentation of the thalli (NCERT page 29).
Q8. Which organisms, along with mosses, are the first to colonise bare rocks, and how does this help other plants?
Lichens. They decompose rocks, making the substrate suitable for the growth of higher plants (NCERT page 29).
Q9. NCERT Exercise Q10(d) matches Sphagnum with moss. Match each with its group: Marchantia, Funaria, Sphagnum, Polytrichum.
Marchantia is a liverwort; Funaria, Sphagnum and Polytrichum are mosses (NCERT pages 29–30).
Q10. In a moss, which is diploid: the protonema, a leaf, the seta or an antherozoid?
The seta. It is part of the sporophyte, which grows from the diploid zygote; the others belong to the haploid gametophyte (NCERT pages 29–30).
Q11. How do mosses reproduce vegetatively?
By fragmentation and by budding in the secondary protonema (NCERT page 30).
Q12. The main plant body of a plant is haploid, has rhizoids and no true roots, and bears flask-shaped female sex organs. Is it a sporophyte or a gametophyte, and to which group does the plant belong?
A gametophyte, since it is haploid and bears sex organs; and a bryophyte. The flask-shaped female sex organ is an archegonium (NCERT page 29), and among plants with archegonia only the bryophytes have the gametophyte as the main plant body; in pteridophytes and gymnosperms it is the sporophyte (NCERT pages 29–30 and 33). Beyond the NCERT Biology text: some algae, such as Spirogyra, also have a haploid main plant body, but they do not bear archegonia.